This research application is a competing renewal as part of the Specific Pathogen Free (SPF) Rhesus Monkey Breeding and Research Program. This application (RO1 RR05092) is intended as a companion to the proposal for a breeding program at The University of Texas, M.D. Anderson Cancer Center, Science Park (U42 RR05080). The proposed behavioral research program is designed to continue to evaluate and improve many behavioral management components of the SPF derivation strategy employed at M.D. Anderson. This program is part of the AIDS Animal Models program of the Comparative Medicine Program of the National Center for Research Resources. Applied behavioral research is vital to the SPF Rhesus Monkey Breeding Program because it addresses societal concerns about the care and treatment of laboratory animals, and because it adds a scientific assessment of behavioral elements of the program which affect production. The objective of the proposed behavioral research program is to scientifically evaluate colony management techniques by combining objective behavioral data with physiological and health data. Studies will focus on the following areas that build upon work done in the first grant period: (1) Documenting the effects of environmental enrichment on rhesus monkeys living in peer groups and in large groups housed in outdoor field cages with the goal of improving well-being. (2) Measuring the effects of several housing procedures providing differing social experience on the development of young rhesus and on their breeding and parenting behavior as adults. (3) Correlating corticosteroid measures and other health-related information with behavioral measures to more fully investigate physical measures of well-being. An additional specific aim, beyond those included in the first grant period, will be (4) Investigating the role that a formal animal training program based on positive reinforcement techniques can play in improving the behavioral management of rhesus monkeys. All of these quantitative behavioral studies will help to assess the effectiveness of the SPF derivation strategy at the M.D. Anderson facility in producing behaviorally competent rhesus monkeys to be part of a self-sustaining population of SPF rhesus monkeys.